Contract Billing - Advanced payment terms - different invoice dates

We are using contract billing to invoice.  We would like to do advance payment terms were we could invoice 12 equal payments due 30th of each month.

It looks like I will have one invoice number and they will have the same invoice date.  Can we have 12 invoice numbers?  Can we have 12 invoice dates?  The due dates are the 30th of each month - that looks correct.

I was also asked if we could start the contract at a Net 30 and cut one invoice.  Then they want to switch the contract terms to a payment plan.  Would the remaining balance then be split into the number of payments? or the whole contract amount?